--- See 'https://github.com/Frege/frege/issues/257 Issue 257'
module tests.comp.Issue257 where

type Lens s t a b = forall f . Functor f => (a -> f b) -> (s -> f s)

foo :: Lens String () Bool Char
foo x i = fmap (const i) (x true)

bar = const (Just 'c')

main = println (foo bar "Okay")
